bug: docs site does not have valid preview image for Twitter

[barriebyron]

When our docs site is shared in Twitter, a preview image doesn't show, probably because the docs preview requires a thumbnail image

The best way to test image preview in Twitter is to compose a Tweet

Interesting to note that LinkedIn posts of the main docs page show an image, because there is image on that page, see https://www.linkedin.com/posts/barriebyron_welcome-mina-documentation-activity-7046485636127580160-5j4F?utm_source=share&utm_medium=member_desktop

However, we want to be able to share any docs page with a preview image. The ideal result is to always show a docs preview image, or at least a logo, for the docs link shares

[barriebyron]

I wondered if this issue would have been closed with https://github.com/o1-labs/docs2/pull/406

@MartinMinkov is there a waiting period before the image for the docs site is available, like in Twitter? I got excited and tried it, but still no preview image